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<div class="titlepage"><div><div><h3 class="title">
<a name="boost_multiprecision.tut.limits"></a><a class="link" href="limits.html" title="Numeric Limits">Numeric Limits</a>
</h3></div></div></div>
<div class="toc"><dl class="toc">
<dt><span class="section"><a href="limits/constants.html">std::numeric_limits&lt;&gt;
        constants</a></span></dt>
<dt><span class="section"><a href="limits/functions.html"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span><span class="special">&lt;&gt;</span></code> functions</a></span></dt>
<dt><span class="section"><a href="limits/limits32.html">Numeric limits
        for 32-bit platform</a></span></dt>
<dt><span class="section"><a href="limits/how_to_tell.html">How to
        Determine the Kind of a Number From <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code></a></span></dt>
</dl></div>
<p>
        Boost.Multiprecision tries hard to implement <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>
        for all types as far as possible and meaningful because experience with Boost.Math
        has shown that this aids portability.
      </p>
<p>
        The <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3690.pdf" target="_top">C++
        standard library</a> defines <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>
        in section 18.3.2.
      </p>
<p>
        This in turn refers to the C standard <a href="http://www.open-std.org/jtc1/sc22/wg11/docs/n507.pdf" target="_top">SC22/WG11
        N507 DRAFT INTERNATIONAL ISO/IEC STANDARD WD 10967-1</a> Information
        technology Language independent arithmetic Part 1: Integer and floating-point
        arithmetic.
      </p>
<p>
        That C Standard in turn refers to
      </p>
<p>
        <a href="https://doi.org/10.1109/IEEESTD.1985.82928" target="_top">IEEE754 IEEE Standard
        for Binary Floating-Point Arithmetic</a>
      </p>
<p>
        There is a useful summary of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>
        at <a href="http://www.cplusplus.com/reference/limits/numeric_limits/" target="_top">C++
        reference</a>.
      </p>
<p>
        The chosen backend often determines how completely <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>
        is available.
      </p>
<p>
        Compiler options, processor type, and definition of macros or assembler instructions
        to control denormal numbers will alter the values in the tables given below.
      </p>
<div class="warning"><table border="0" summary="Warning">
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<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../doc/src/images/warning.png"></td>
<th align="left">Warning</th>
</tr>
<tr><td align="left" valign="top"><p>
          GMP's extendable floatin-point <code class="computeroutput"><span class="identifier">mpf_t</span></code>
          does not have a concept of overflow: operations that lead to overflow eventually
          run of out of resources and terminate with stack overflow (often after
          several seconds).
        </p></td></tr>
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<td align="right"><div class="copyright-footer">Copyright © 2002-2020 John
      Maddock and Christopher Kormanyos<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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